Grinding machine



June 10, 1952 'A. H. DALL 2,599,698

GRINDING MACHINE Filed March a, 1950 s Sheets-Sheet 1 4 TTO/PNE VS June10, 19 2 A. H. DALL 2,599,698

GRINDING MA Filed' March 3, 1950 8 Sheets-Sheet i6 INVENTOR.

flLEE/FT'H, BALL '1? Y FiQE. 5U

June 10, 1952 A. H DALL 2,599,698

GRINDING MACHINE Filed March 3, 1950 S-Sheets-Sheet 3 INVEN TOR.

flLBERT H, DflLL June 10, 1952 A. H. DALL GRINDING MACHINE Filed March3, 1950 8 Sheets-Sheet 5 Fig-'7 l w 7* 45/ e4 1 we 88 E June 10, 1952 A.H. DALI. 2,599,698

GRINDING MACHINE Filed' March 5, 1950 8 Sheets-Sheet e INVENTOR.

' flLBE/FT H, DflLL BY June 10, 1952 A. H. DALL 2,599,698

GRINDING MACHINE Filed March 3, 1950 8 Sheets-Sheet 7 INVEN TOR. H0flLBE/FT H, DflLL BY /jj 22 21% Hz June 10, 1952 A. H. DALL GRINDINGMACHINE Filed March 3, 1950 8 Sheets-Sheet 8 i w mvz Patented June 10,1952 UNITED: STATES PATENT @FFECE.

GRINDING MACHIN E Albert H: Dall, Cincinnat Cincinnati Milling M Ohio,aroma-ration of i, Ohio, assignor to'The achine- 00., Cincinnati, OhioApplication March 3, 1950, Serial No. 147,507

17 Claims;

ing machine disclosed in'application of-Dallet al., Serial No. 741,076,which issuedas Patent'No. 2,567,558 on May 16, 1950;

One of the objects of the. present inventionis the provision ofagrinding machine capable of;

utilization in the production of work;of1maxi+ mum precision due. toelimination of vibrations due to unbalance. in the grindingstructure-and the provision of supplemental meansfor control. ofrelative movement. of parts'of the machine.

during final finish grinding operations.

A further object of the presentginventionis the provision of a grinding,machine constructed; to

avoid damage to the; work dueto springingof the;

parts of the machine duringa finishing operation andwhich will maintainasubstantially constant minimum pressure between grinding wheel andworl: during such finishing operation.

An additional object ofthe invention is-theprovision in a grindingmachine of improved means;

for selectively controlling the nature; of the mounting orsupporting ofthegrindingwh-eelj spindle during the performanceofdifferent-openation-s by the machine.

The present invention furthercontemplatesthe provision of controlled*resili-entymeans for deter? mination of thenature and extentOf-gengagement of-the grinding wheel and worlrcluringa surfacingoperation and'of novel structuraldetailsgfor accomplishment of this 4and the above referred" to objects.

Other objects and advantages-of? the'present" invention shouldbereadi-ly apparentbyreference. to the following specification,considered 'irrconjunction with the accompanying drawings form? ingapart thereof; anditistobe understood-that any modifications may be madein the exactstructural details there shown and described;

within thescope of-the appended-claims,withoutdeparting fromor exceedingthe spirit of *the'invention.

Figure -1 is-a sectional view of the spindle por tion and associatepartsof a grinding machine;

embodying the present invention.

Figure 2 is a transverse'sectional viewon the line 2--2 of "Figure 1.

Figure 3 is a fragmentary sectional view of one form of' spindleclamping-- means taken on the line 3-3 of Figure 1.

Figure 4-is a vertical-section on theliIieM- -Q ofFigure 3. t

Figure 5 is a. fragmentary vertical sectional the gage mounting.

Figure '7 is a fragmentary front view of the controlvalve bracket asutilizedcin connection with the mechanism illustrated in Figure 1.

Figure 8 is a vertical section on the line 88 of Figure 7;

Figure 9 is a horizontal section on the line 9-9 of Figure 8.

Figures 10, 11, 12, and 13 are diagrammatic views-illustrating differentconditionings of the hydraulic controlcircuits of the machine effectableby the valve and control mechanism. shown in Figures Ho 9.

Figure 141s a fragmentary vertical sectional view illustrating amanually operable clamping means for the grinding wheel spindle.

Figure 15. is a view in elevation of a modified form of hydrauliccontrol valve assembly.

Figure 16 is a vertical sectional view as on the line |6-l 6. of Figure15.

Figuresl'l to 19 are diagrammatic views of the controls selectivelyeflectable by the valving mechanism of'Figures and 16.

Figure 20 is a diagrammatic view of another modifiedform of the presentinvention.

In the drawings the reference character 29 designates the base or bed ofa cylindrical grinding machine having the ways 2| and 22 mounting themovable wheel head 23 which supports the spindle for a grinding wheel24. The detail mounting 'of-the spindle 24 is substantially thatillustrated and claimed in pending application, Serial No. 741,076,which issued as Patent No. 2,507,558 on May 16, 1950. It includes thespindle housing 26 having mounted at one end the hearing structure 2'!supportingthe right handend of the spindle for rotary and slight axial.oscillatory or gyratory movement. At the left hand portion-of the"machine there is mounted inthe housing 26"a sleeve 28' locked inposition as-by screws'29 and-having secured in position therein anorbital series of tubes 3|. The opposite endsofythese tubes and rods areheld byresilientbushings of Neoprene? or similarmaterial 32 in bearingsleeve 33 whichcircurnscribes the left handportionof the spindle 24' andis supported for limitedmovementgwithinthe housing 262 It will be notedby;reference-to Figure lth'at the resilient rods and-tubes are mountedat a slight angle to-the horizontal axis of'the spindle, or

spring, rods v and, conduitv apertures formedin the.

alternatively, may be given a permanent flexure or set in an upwarddirection so that their resilient action normally will tend to urge thesleeve 33 upwardly or away from seating position as respects the housing23. As a result of this construction, the wheel bearing end of thespindle is yieldable or resiliently supported by the tubes and rods withits outer bearing sleeve in clearance relation to the housing such thatthe spindle and its bearing unit may freely vibrate or oscillate aboutthe bearing 2? as a center for the purpose of unit balancing or otheroperations as hereinafter described.

Contained within the bearing sleeve for effecting an automatic centeringof the spindle with respect to the sleeve under varying load conditionsare the conventional rocker shoe bearings 34 supported in position as bypivoted studs 35 and cage unit 39, suitable portings as at 31 beingprovided from the bores of the resilient tubular members 3| for supplyof lubricating medium under pressure as through the piping 33.

Formed at the end of the spindle is a counterbore 39 receiving thebalancing balls or weights 49 normally locked in position by the disc 4|urged into said locking position by spring 42. A piston plunger 43slidable in cylinder 44 is actuable by pressure medium introducedthrough porting 45 from the tube 3| which may be utilized to move thepiston 43 outward to effect temporary unclamping of the weights or balls49 for effecting dynamic balancing of the parts.

In conditioning the machine for grinding operations, the spindle 24 isrotated by power applied to the multiple sheave 55, and the piston 43 isinitially hydraulically outwardly urged to release the members 43 andpermit them automatically to take up the necessary positions foreffecting proper vibration eliminating dynamic balancing of the wheeland spindle structure. The hydraulic pressure is then released orreduced so that the member 4! will move to position to clamp thebalancing devices in this automatically selected position.

For performance of normal grinding operations, truing of the grindingwheel and the like, it is desirable that the spindle be maintained in afixed or non-shifting position with respect to the wheelhead. This maybe accomplished automatically by utilization of a mechanism such asparticularly illustrated in Figures 3 and 4, for example. As thereshown, the sleeve 33 is provided with a hardened insert or anvil 41engageable by the ball or other hardened tip 49 on the plunger orlooking member 49. This plunger has a piston portion 59 slidably in thecasing and outwardly urged by spring 52. Mounted in a slot of the pistonportion is a wedge block or link 53 constituting a clamp actuatoroscillatable about pin 54 on the interposed bearings 55, wherebyprovision is made for free adjusting movement of the link under pressureconditions.

The casing 5| is provided with a transverse bore providing opposedcylinders as at 53 and 51. Slidable in these cylinders are the flangedpiston bushings 58 and 59 which, in turn, support for sliding movementthe clamp piston 69 having the terminal cylindrical piston portions 3|and 62 and the intermediate slotted body portion providing thefurcations 63 and 64, the clamp link or lever 53 fitting into the slot65 between these furcations. The position of the link in the slot andits movement with the piston 69 on reciprocation thereof is controlledby the antifriction rollers 66 and 61 carried by the pivots 68 and 69extending transversely of the slot and connecting the members 63 and 64,the members 66 and 51 being disposed in close interfitting but rollingengagement with the opposite sides of the member 53.

Extending transversely of the casing 5| and disposed above thetransverse bore therein is an abutment stud comprising the co-axialportions 68 and 69 journaled in the casing 5| with an intermediateeccentrically disposed portion 10. The stud is provided with a head ornut-like member as at H to facilitate rotary adjustment and thuspositioning of the eccentric i0 and can be locked in desired rotativeadjusted position by screw 12. Mounted on the eccentric are theantifriction bearings 13 rotatably supporting an adjustable abutment inthe form of a roller 14 in position to engage the upper arcuately formedcam or eccentric wedge terminal portion 15 of the clamp link or lever53.

By reference to Figure 3, it will be noted that introduction of pressureinto the cylinder or piston chamber 51, as through conduit 16, serves toforce piston 62 and. piston bushing 59 to the left, roller 61correspondingly moving link 53 which by reaction between roller 14 andsurface 15 tightly forces the clamp plunger 49 downward against thebearing sleeve 33 to clamp the sleeve in position within the wheelheadhousing so that the spindle is rigidly locked in place with respect tothe housing as indicated in Figure 1.

At this time it will be noted that the shoulder 11 on the web orfurcation B4 of the piston member has moved to the left a distancesufiicient to clear the end of the piston bushing 59. At this point thepiston is in its extreme left hand position and the flange 18 on thepiston bushing 58 has a clearance as respects the stop shoulder 19 ofthe member 5|.

In the event that it is desired to efiect a slight release of theclamping action while maintaining a controlled and predeterminedsteadying of the bearing sleeve 33, pressure may be introduced into theleft hand end of the cylinder 53 by way of conduit 89 while pressure isstill maintained in the conduit 16. This pressure will react on thepiston bushing 58 moving the same to the right until the flange of thebushing is seated against the casing 5| while at the same time theshoulder 1'! of the piston member will be seated against the bushing 59.With the parts in this position the piston is, therefore, rigidly heldagainst movement in either direction and the clamp link 53 and. plunger49 correspondingly rigidly maintained in position to limit any upward orvertical movement effected by the reaction of the spring rods 30 andtubes 3| as respects the bearing sleeve 33. Dispositioning of thesleeve, however, permits of a limited back and forth oscillatorymovement of the sleeve and thus of the grinding wheel spindle 24 andwheel 25 as guided by the inter-engagement of the tip 48 with anvil 41.The arrangement of the spring rods or supports for the sleeve is suchthat their automatic influence normally effects the upward releasingmovement only. To create a controlled inward or forward yieldingdeflection reaction as respects the bearing, a spindle, tending toyieldingly maintain the wheel in engagement with the Work, use is madeof the plunger 8| slidably mounted in the bushing 82 secured in the rearportion of the wheel head 23 and normally held in retracted position asindicated in Figure 5 by the spring 84. A compression spring 85contained within sleeve 86 carried by the bushing 82 51 bears: atyone.endagainst. the member. 8 I and at; its 1 outer end; against: thehydraulically ac.- tuable piston- 81, actuating medium for.=.the. piston81 being supplied through conduit 88 connectedtoqthe outer'end ofsleeve'86.; Itwill be evident that movement toward the left of piston81. will. tend to, compress spring-.85, overcoming.the.-force:of;spring, to. an extent dependent upon the, pressure,created. againstpressure 81 and.-.thus1;-shiftxmember; BI toward theleft and into; engagement with the. bearing sleeve 33;

the.; s1eeve: 33 .to register the. extent ofits con-.

trolled; resilient movement; By observations of the extenttofthis;movement? suitable adjustmentsxmaybe-made of theactuating pressure introduced through; the conduit 88. and thus the permissible-movement of.the resilient supported grinding wheel during. this finishing operation.Therstructure andgmanner of control .of the parts just-described, willbe particularly apparentby.

reference to; Figures 7. to 13 inclusive. Mounted on'thezbase or bed2010f the. machine: is a control bracket 92: having: a bore inv which ispressed bushingzi93 .:receiving the.;rotatable valve member.

94actuableoby handle 95. These parts are of conventional hydraulic valvedesign in which the bushing 93, is provided with a series of externalcircumferential groovesiorming in connection with;the bracket 92.aseries of axially spaced closed-passages, having inwardly extendingportings asindicatedlin Figure-8 for cooperation with thegpvalvenmember94-. This valve member is, in turn; provided with acentralbore, andinterconnectedtamrular and axially extending grooves bywhich-varioushydraulic porting connections may begefiected asparticularly illustrated in Figures 10i1to. 13.;inclusive.

Suitable, hydraulic pressure creating devices are;;employed, such as.the pump 96 having an intake. at .91extending into the tank or reservoir98;;anda pressure conduit99, the amount of pressure being controlledasby relief valve. I00. A branchconduit IOI extending from the conduit 99through pressureqreducing valve I02 supplies byawayof conduitI03wlowpressure hydraulic mediumi as for; power lubrication asdistinguished from;actuation. purposes while a return conduitIMrprovides a reservoir; connection for exhaust of fluid: from theseveral potential actuating mechanisms; As shown inFigure 8,. thisconduit llyiS COIltiDllOllSlYj coupled bya port I05 with thei roove I06ofvalvestand thence to the surfacmgroove .I 01 in-said valve whichextendsin an axial direction to the extent of grooves I08, I09 andIIIlofthe'. bushing 93. By selective rotary positionings of the valve,this groove may therefore be;alignedjwithjproper portings ofthe bushinsuch 1 as. .theporting III of groove IIO to couple :theseveral groovesto reservoir in one or morepositions.of;the:valve member. Thevalve isProvided.with..a.,second groove] I2 extendingccir- 6 cumferentiallyaofazmajorportionthereof isoithat conduit I .I 3; will be coupled with:reservoir during. most I of the positionings thereon.

The valve" body. 9411s provided; with: acpthird peripheral groove as at,I I4 in; constant, com-t munication: with the; 1 main 1pressurerlconduit 99 by way ofjport H5; This groove communicates throughthe cross. drilling; or, passage I16 with theaxial pressure bore: II1in-the valvetbody whichextends through most .of then-length of the valvebody and is selectively; couplable: with: various .of the-controlgrooves; such asv I08, I09; and; I I ;0',by means of.:the..selectedradial portings such as;v I .612 in the-valve body. 9.5..

The primary "connections for; varioustselected operations of themachine. have been; diagram.-. matically illustrated in Figures 10 to":l3..:inclue; S1Ve.

InFigure: 10, asinsEigure 7, thecontrolhandle 95 -for determination ofthe position of thezyalve, body 94: is indicated in its. extremeleftrrhand. or. counterclockwiserposition. In: this: position the lowpressure conduit I03iistscoupled jby way ofbushing groove II8-,port-.IIQ; valve? groove I29; surface grove; I2I-, port.I60,groovem-Ifirlrto piping; 38:- extending to. the clamp.release-cylin-. der 44 and to: the bearingcylinder; 33 forluhrie cationat low pressure .of: the; bearing zslioesrflr- At ,the; same timethe:high pressure-conduit 99' igcoupled: by way: of; groove.::I I0.and-.l.conduit-.

15*, to I the; right hand piston chamber: 5:'I:.for: clamping. theparts. in the position.indicatediin Figure-13; In this position the left.h-andpiston: chambere andiconduit 88' to the .resilientspindle.

backing up structure particularly illustratedtin Figure 51 are connectedto FIQSBIVOH.

The mainqspindle. by-virtue of the: secure. clampingofiits bearingsleeve 33;is .thus.l rigidly.

held-in position-within the wheelheadandrthe machine continued for whatis; known as roughgrinding or.- apprecia-ble stock. removal 1 from awork piece for truing or; other standardaoperations. Inthis mannertheessentialstock removal andproper generation of the desired cyl-indri-.-.caljor-like surface ofirevolution on a worlcpiece may. be rapidly andsatisfactorily effected;

However, whenitisdesiredto produce an 18X: tremely accurate surface or.surfaces. of high finish, as.v for exampleuini the, grinding.ofyrollsfor. use in productionof: metal foil or thelike ithas been foundthateven with most. accurate setting of the partscapable with ordinarygrinds ing machine constructions, during theifinal finish grindingoperationthere is a certain tension;re-

, lease in thepartsof the grinding machine.

may cause. a, grinding wheel to slightly. diginto: or mars the, highly.polished surface. which it is desired to produce within an, accuracy oftenthsof thousandths. ofan inch. Likewise even. the slightest-.run-out;of the wheel. spindle :or surface of the wheel:duringsuchfinishing op-.eration may produce like deleterious results,

These are, eliminated or.-minimized to a.maximum extent by utilizationofthe parts-hereinabovedescribed in the-manner indicatedrin connectionwith the diagrammatic view; Figure 11; Here the control handle 95 hasbeen shifted in a clockwisezdirectionto the position indicated" in thedotted lines in Figures '7 and 11 As there indicated, the low pressurelubrication conduit I03Lis still coupled with the spindle bearing andclamp 1 structures, maintaining a low pressure but of 'insufficientamount to causeanyloosening of the balance mechanism clamping device.-The high pressure. throughconduit: 99," however, is

coupled by way of the central bore III of the valve body to groove III)and conduit 16 as before, but additionally to groove I09 and thence toconduit 80, causing balancing pressures against the piston bushings 58and 59 so that the clamp 49 is slightly released, freeing the bearingsleeve 33 for slight resilient movement of the spindle 24 as previouslydescribed. At the same time the pressure bore I II is coupled by way ofgroove I08 to conduit II3, discharging into chamber I2I whence it passesby way of the spiral resistance groove I22 to permanent reservoirconnection I23. This resistance is variably adjustable with respect tothe intermediate pressure conduit 88 by means of the adjusting screw I24so that the value of pressure in conduit 88 reacting against piston 81can be delicately adjusted and controlled.

It will be evident that in this particular relationship of the parts theclamp 49 is sufficient- 1y released so that the member 3 and spindle areslightly upwardly deflected to an extent limited by the locked positionof the members 53-49 and at the same time any pressure between thegrinding wheel and work will tend to exert a yielding rearwardly of thegrinding wheel by fiexure of the rods and tubes 30 and 3I which normallyhold the spindle axis in a fixed vertical plane. The amount ofresistance to such pressure effected fiexure of these resilientsupporting members or the maintenance of the various parts under apredetermined light pressure against appreciable fiexure or displacementis determined by the setting of the variable resistance I22 determiningthe reaction of the spring 85 against the plunger. In this manner thegrinding wheel is maintained against the work with a very light pressurebut in a manner entirely independent within the fine limits underconsideration of any possible slight relative springing action of thework support and grinding wheel support and the wheel itself through theflexible mounting of its spindle being permitted automatically to adjustor compensate for any slight outof-round or other irregularities ofeither the wheel surface or work surface, permitting production of anextremely accurate surface of high finish and preventing damage to worksurface during this final finishing operation. It will be appreciatedthat this resilient action may involve a very slight substantiallyconstant horizontal angular displacement of the grinding wheel spindle,slightly varying the previous parallelism existing. between the wheelsurface and .work surface or alternatively that if the wheel has beenworn slightly from a true cylinder during previous grinding operations,such tilting may restore the parallelism. In the event that theseimprovements are applied to a standard universal grinding machine orgrinding machine in which the work support or table has a verticalpivotal mounting or swivel adjustment, the angle of relative traverse ofthe work and grinding wheel surface may be set exactly parallel to avoidany feed line or other deleterious markings on the work'surface, thusattaining utmost satisfactory action in connection with the finalresilient or yielding engagement finishing operation.

When the control handle 95 is shifted to the second dotted line positionas shown in Figure '7, or the position-indicated in Figure 12, it willbe noted that pressure is coupled .to the conduit 80, completelyreleasing the clamped mechanism while the conduits I5 and H3 are coupledto reservoir. In this condition, the spindle bearing unit 33 iscompletely released for checking up as to the balanced condition of thespindle and grinding wheel.

Further movement in a clockwise directionto the third dotted lineposition in Figure 7 or the Figure 13 position maintains this releasedor unlocked condition of the spindle but at the same time couples thehigh pressure conduit 99 with the piping 38, building up the generalpressure in the bearings and at the same time a suflicient pressure inthe chamber or cylinder 44 to release the balancing member clamp 4I sothat the balancing elements 48 may be moved automatically by vibratorycentrifugal force resultant fromany out of balance condition to take upthe necessary position to counteract and compensate for said out ofbalance condition in the spindle and-as The spindle having beenpersociated parts. mitted to run in this condition sufficient time forthe weights properly to establish their position and dynamically balancethe structure, the handle is shifted back to the Figure 12 position fortryout as to correctness of the automatic balancing and then moved intoeither the Figure 11 or Figure 10 position, depending on whether a stockremoval type grinding or a strictly finishing type grinding operation isto be performed.

In this connection, attention is invited to the fact that by theemployment of the yielding bushing mountings 32 for the members 38 and3I, while the parts are firmly and securely anchored in position, aslight relative angling movement is permitted, eliminating thepossibility of any canting or tendency to misalignment of the bearingunit 33 and contained parts when moving from clamped to unclampedposition or when freed for spring pressure grinding operations.

In Figures 14 to 19 there has been illustrated a slightly modified formof control mechanism in which the control of clamping of the floatingbearing sleeve 33 is manual in place of hydraulic. In this instance thehousing 26 supports the sleeve nut I24 receiving the clamp screw I25having at its upper end the operating or pilot wheel I25, and at itslower end the stud position I2! is movable into clamping engagement withthe hardened insert I28. It can be understood that as in thehydraulically controlled form the downward movement of the stud I21 maysecurely lock the spindle in position within the housing. Alternatively,a slight loosening will allow of the necessary free floating for thefinal grindin operation. To facilitate determination of the exactbacking off from clamping position, the sleeve I24 is preferablyprovided with suitable graduations at I29 for cooperation with thepointer I30 on pilot wheel I26.

The functions of release of the balancing members and of control of thespring backing up pressure for the spindle movement during finishgrinding are determined as before by suitable couplings of hydraulicpressure which is elfectable through the positionings of valve I 3Irotatable by handle I32. This valve is mounted within the casing I33which corresponds in substance to the valve block or casing 93 andcontains a hydraulic resistance varying element I34 corresponding in allrespects to the member I24 of Figure 9.

As particularly illustrated in Figure 16, the pressure conduit 99 'ofthe hydraulic system is coupled to the outer groove I35 of the valvebushing I36 and thence by way of porting I31 to the valve groove I38 andthrough port I39 to the -central pressure chamber or bore I40 axiallydis-' posed within the valve. Likewise, the exhaust or return conduit I04 is connected to'thepassage I 4| in the valve block I 33 1 and by wayof porting I142 to the outer groove of the bushing and thence throughporting 143 to the distributor groove I44 circumscribin the valve bodyI3I. An additional porting I45 connects by way of groove I46, portingI41 with the drain groove I48, in turn'coupled 'bypassage I49 to thespace I50 back of thepistonportion II of the variable resistance controlvalve I34 to take care of any leakage into thisspaceand prevent buildingup of back pressure condition.

"The peripheral "groove I44 communicates with a groove or passage I52preferably extending'in an axial direction on the surface of "the valveI3I and selectively couplableas bythe portings I53 and I54 with thegrooves I55 and I55 of the bushing. Groove I55 of the bushing is coupledby way of conduit l59 with "the piston chamber 44 for effecting releaseof the balancing ball clamp head I4I while groove I56 is correspondinglycoupled with the passage or conduit I51 extending to the variableresistance control groove I22a.

The several hydraulic couplings efiectable by movement of handle I32 andthus of valve I3I to its different positions, as illustrated in'Figure15, will be best understood by reference to the diagrammatic views,Figures 17, 18, and 19. InFigure 17, thehandle has been indicated inits-left'hand position'sothat the parts are conditioned for a finishgrinding operation. In this instance, the conduit I59 is connected byway of the peripheral groovings of the valve to the exhaust conduit I04while .the pressure conduit 99 is connected through the central bore orpassage I40 and the porting topassage I51 leading to the resistancedeterminator I22a introducing the .selected pressure through theintermediate take-off conduit 88 to react on the piston 81 and thusdetermine the force exerted by spring 85 by way of member. 8| againstthe sleeve 3, limiting its rearward movement under the effect ofgrinding pressure.

This operation and the structural parts are the same as those previouslydescribed in detail in connection with Figure 5 of the drawings.

When thehandle I32 is moved to its central position, as shown in thefull lines in Figure 15, the circuit is conditioned as indicated inFigure 18. In this form the conduits I59 and I57 are both coupled to thereturn' or low pressure conduit'I'Il I while the pressure conduit 99 isblanked off as respects reaction on any of the pressure shiftable.elements. Inthis position, ifthe screw 125 is in its lowered or clampingposition the machine isjconditione'd for regular grinding or truingoperations Whileif it is released, the balanced condition of the machinemay be determined.

When in this released position, if it is desired to effect automaticreadjustment of the balancing mechanism the handle is thenmoved .in aclockwise'direction to a third position indicated in "the dotted linesin Figure and diagrammatically in Figure 19. In this position it will benoted thatthe pressure conduit 99 is coupled by way of I40 to thebalancing ball release conduit I59 while the conduit I51, as well asconduit I'2 3,'are connected to reservoir sothat'there is noreactiononthepiston 81.

From the foregoing it will be evident that in connection with areleasableor potential resilient or free mounting of the grinding wheelspindle, permitting of a limited back and forth play'of the same so thatthe amount of resistance to horizontal movement may be controlledtoeffect a very light resilient pressure of the wheel and spindle as anentirety toward the-work, which movement, being relative to thewheelhead, will be independent of release of any slight mechanicalstress existing between the supporting bed or base and the wheelheadwhich might otherwise interfere with the accuracy of finish oflthe workpiece. It will be further noted that for utmost efficiency the amount ofthis spring action may be controlled by avariable hydraulic pressure,reacting against the grinding wheel spindle in a direction toward thework, the strength and compressibility of-the intervening spring 85shown determining whether the'reaction of the hydraulic pressureon;piston 81 effects a direct or resiliently dampened action as respectsthe pressure .or potential fluctuation of this spindle. It will also.be.noted that in both of the .forms shown operation of a single'leverdetermines the conditioning of the machine for balancing, grinding, and,finish grinding operations, although the actual lockingo'f'the spindleagainst vibratory oroscillatory movements .may be effected eitherdirectly manually or indirectly through hydraulic .mechanism also underthe control of said lever and valving.

It will be understood that "the present invention may be employed withvarious forms, of-conventional grinding machines, as for, example, themachine shown injPatent "2,101,644. As .diagrammatically illustrated inconnection with Figure ,10, the machine includes Ways 161,, [68 formedon the bed 20 which SHPPOitjthereQiprocating carriage I59. Swiveled onthiscarriage as at 163 is the table I64 provided with work supportingmeans I65 for maintainingthe ,work piece I66 in proper opposing relationto "the grinding wheel 25. In thisform-of machine, the in and out orfeeding movement is appliedto the grinding wheel while the relativetranslatory movement is. effected by axial shifting 'of .the work pieceand its supportingtable-and carriage along the .bed120. Due to thepivotal connection between the carriage and work table it isipossible,if desired, during thefinishing operation ;to effect a slight angularpositioning of the axis and thus the surfaceof the work with respect tothe axis of the spindle housing 26. This adjustment may also be effectedby slight angling of the'wheel spindle support as provided in variouscommercial grinding machines. This permits ofjoompensation for anyminute angular displacement of the surface of the wheel 25 due to thepotentially.free horizontal movement of its Spindle during the finishingoperation so that the surfaces of the wheel and work maybe maintained.egwexactly parallel, thus reducing the possibilityof formation of feedlines on the work due to greater pressure of one edge or the other ofthe wheel against the work.

Figure 20 illustrates diagrammatically anadditive feature of theinvention capable of utilization with the forms previously described andparticularly adapted for employment when 'extremely light finishing cutsare being taken or in instances where the relationship of work andgrinding member may be such as to tend to cause slight undesirablevibratory movement of the grinding wheel'spindle. This form is-mosta'dvantageously utilizable, for example, inthe'final finishingof largerolls which frequently are-several feet in diameter by ten feet or morein length. Such rolls are used for production of metal foil or the likeand must be of extreme accuracy and unblemished surface throughout.

As has been previously pointed out, the mounting of the grinding wheelspindle 24 and its releasable journal or hearing sleeve 33 are such,that as an entirety they may pivot about the bearing 21 when theclamping element 48 is released. In Figure there has been illustrated indetail the yielding pressure member BI and associate elements forreaction on the member 33 to effect an urge of the spindle 24 in adirection to effect engagement of its supported grinding wheel 25 withthe work piece I66.

It will be understood that this is entirely sufficient and effective formany grinding operations. On the other hand, there may arise conditionsin which an irregularity in form or mounting of the work piece or othergrinding conditions may tend to create a variance in position of thegrinding wheel during traversing which might set up a vibratory reactionin the spindle 24, or in which it is desired that a greater potentialbacking up pressure be given to the spindle to resist rearwarddeflection by work engagement, which pressure will be of a nature tomore than overcome the force of the resilient axial centralizing memberssuch as 3I.

For greatest operating efiiciency under these varying conditions, theremay be provided at a suitable point on the housing or support 23 asupplemental housing I providing a cylinder I1I to receive a pusherpiston I12 as has been indicated in Figure 20. By reference to thisfigure, it will be noted that the diameter of the cylinder and chamberis preferably less than the diameter of the cylinder for the piston. 81with the result that if equal pressures be introduced into therespective chambers for reaction on these pistons a. greater force willbe exerted by the piston 81 than by the piston I12, creating apredominating urge of the spindle and its supported grinding wheel inthe direction of the work to counteract the reaction force between workand grinding wheel during the grinding operation. In Figure 20 there hasbeen indicated, as in preceding views, the conventional pressure source96 which may be coupled by valving mechanism as heretofore described tothe conduit II3 extending to the variable resistance groove I22 so thatthe pressure reaction may be varied as respects the conduit 88.Branching from conduit 88 is the auxiliary pressure conduit I13 coupledwith chamber I1I for actuation of thepiston I12; varying the effectivepressure in conduit 88 will proportionately vary the pressure reactionsagainst the respective pistons. The conduit I13 has been shown asincluding a resistance or choke coil I14 to retard or damp out the flowreactions between the cylinders for pistons 81 and I12. pressure isbuilt up in conduit 88, since there is no separate drain or outlet forthe chamber I1I, equal unit pressures will be created as respects therespective pistons although a different actual force will be exertedtherein due to the differential between the piston area on which saidunit pressure reacts. The choke I14, however, will damp outinstantaneous pressure reactions between the cylinders produced bypressure variants on the wheel 25 or otherwise, thus steadying andstabilizing the pivotal or floating action of the spindle 24. The pistonI1I thus acts as an opposed yielding resistor which reacts on the Itwill be understood that as 12 spindle in opposition to the pressuremembers The viscous damping coil I14 serves to damp out anyhighfrequency motions due to close pitched undulations in the work piececaused by prior grinding operations. On the other hand, the coil willnot damp out motions caused by runout of the work piece which haverelatively low frequency motion. Nor will it damp out motions caused byslight changes of parallelism of the work periphery and its direction ofmotion.

These changes in work run-out and parallelism are the result of thermalchanges in the work piece or machine during long finishing operations onsuch things as large rolls for rolling mills.

On finishing operations on rolls, the condition of the face of thegrinding wheel is very critical. Constant pressure between this face andwork is highly desirable over long periods. Changes in work dimensiondue to temperature will create large variations in pressures betweenwheel and work where the wheel is held very rigidly. Thus, it isdesirable to have in a machine the possibility of holding the wheelrigidly for rough grinding and elastically for finish grinding, such asis attained by the hereinabove described structures.

What is claimed is:

1. A grinding machine including a bed, a work support and a wheelsupport mounted on the bed for relative reciprocating and feedingmovements, said wheel support including a housing member, a wheelspindle supported within the housing member for yielding movementrelative thereto, said spindle having a wheel supporting portion, meansfor yieldingly urging the wheel supporting portion in a direction towardthe work support, said means for yieldingly supporting the spindleincluding deflectable resilient members having a portion fixed withrespect to the housing and a second portion fixed with respect to thewheel supporting portion of the spindle, said means for yieldinglyurging the wheel supporting portion of the spindle in the direction ofthe work support including a pressure actuable piston, a source ofpressure medium for supplying pressure to the piston, and a pressureregulator for determining the reaction force exerted by said means onthe piston.

2. A grinding machine including a bed, a work support and a wheelsupport mounted on the bed for relative reciprocating and feedingmovements, said wheel support including a housing member, a wheelspindle supported within the housing member for yielding movementrelative thereto, said spindle having a wheel supporting portion, meansfor yieldingly urging the wheel supporting portion in a direction towardthe work support, said means for yieldingly supporting the spindleincluding deflectable resilient members having a portion fixed withrespect to the housing and a second portion fixed with respect to thewheel supporting portion of the spindle, said yielding means for urgingthe wheel supporting portion of the spindle in the direction of the worksupport including a separate expansion spring element, a piston backingmember for said spring element, and a source of pressure medium forsupplying pressure to urge the piston against the element.

3. A grinding machine including a bed, a work said wheel supportincluding a housing member,

a-Wheelyspindle.supported within the housing :member foryieldingmovement relative thereto,

:said spindle having a wheel supporting portion, meanscfor yieldinglyurging the wheel supporting portion in a direction toward the worksupport, saidmeans for'yieldingly supporting the spindle includingdeflectable resilient members having a vportionfixed with respect to thehousing and a second portion fixed with respect to the wheel supportingportion of thespindle, said yielding 1 means for urging the wheelsupporting portion of the spindle in the direction of the Work supportincluding a separate expansion spring element, a piston backing memberfor said spring element, asource of pressure medium for supplyingpressure to urge the piston against the element, and a pressureregulatorto adjust the pressure reacting on said piston.

4. A grinding machine including a bed, a work support and a wheelsupport mounted onthe bed for relative reciprocating and feedingmovements,

said wheel support including a housing member, a wheel.spindlesupported--within the housing member for yielding movement relative thereto,

said spindle having a wheel supporting portion,

member, a wheel spindle supported within the housing member for yieldingmovement relative theretmsaidspindle having a wheel supportingportion,.means for yieldingly urging the Wheel supporting portion in adirection toward the Work support, and a locking device carried by .thehousing and reacting on the spindle rigidly to secure the spindle inposition withrespect to the housing, said lockingdevice havng afirsthydraulically determinable position for rigidly securing the spindle andasecond hydraulically determinable position for effecting a limitedrelease-of the locking device with respect to the spindle, a source ofhydraulic actuating. medium and a two-position valve intervening thesource and the locking device and selectively positionable todeterminethepositions of thelocking device effectable by said hydraulic medium.

6. A grinding machine including a bed, a work support and awheel supportmounted on the bed for relative reciprocating. and feeding movements,said wheel support including a housing member, a wheel spindle supportedwithin the housing member for yielding movement relative thereto, saidspindle having a wheel supporting .portion, means for yieldingly urgingthe wheel supporting portionin a direction toward the work.support,andalocking device carried bythehousingand reacting on .thespindlerigidly to secure .the spindleiin position'with respectto the housing,said locking device having a .first hydraulically determinablepositionfor rigidly securing the spindle and a secondhydraulicallydeterminable position for .eifecting ,a limited release of the.lockingdevice with. respect to. the spindle, a source dtlhydraulicactuating medium and a twopusher member in the position valveintervening; the source :and :the locking device and .selectivelyipositionablegto determine the positions-of the locking deviceeffectable by said hydralic medium, "a pressure device engageable withthe spindleto effect a directional urge against the spindle, said pressure device including a hydraulically shiftable piston, the .valvehaving conduit portions for determining the eifective coupling of'thesource ofxpressure medium with said, piston to eiTect said directionalurge.

7. A grinding machine including a bed,.a work support and a wheelsupport mounted on the .bed for relative reciprocating and feedingmovements, said wheel support including a housing member, a wheelspindle supported-within the housing member for yielding movementrelative thereto, said spindle having a wheel supporting portion, meansfor yieldinglyurging thewheel supporting portion ina direction towardthe work support, and a locking device carried by the-housingandreacting on the spindle rigidly to secure the .spindle in positionwith respect to t-he.housing, said locking device having a firsthydraulically determinable position for rigidly securing the spindle anda second hydraulically determinable position for effecting a limitedrelease *ofthe locking device with respect to the spindle, a source ofhydraulic actuating medium and-atwoposition valve intervening the sourceand the locking device and selectively positionable to determine thepositions of the locking device eifectable by said hydraulic medium, apressure device engageable with the spindle toeffect a directional urgeagainst the spindle, said pressure device including a hydraulicallyshiftable piston, the valve having conduit portions for determining theeffective coupling of the source of pressure medium with said piston toeifect said directional urge,'and a pressure variator'for.determiningthe force hydraulically exerted against said piston.

'8. A grinding machine spindle structure including, ahousing or support,a first spindle bearing mounted on the support for oscillation relativethereto, a second spindle bearing, means resiliently supporting thesecond spindle bearing for bodily movement relative to the support, agrinding wheel spindle journaled in said bearings, releasable clampmeans for rigidly securing the. resiliently supported bearing inposition on the support, a pusher member carried by the, housing inposition to engage and effect a unidirectionalurge against theresiliently supported bearing, and means for actuating the pusher memberin thedirection of the bearing, whereby on release ofthe clamping meanssaid pusher member will be effective for oscillating the spindle andsaid-first bearing for determining the position of the resilientlymounted bearing and the spindlesupported therein with respect-to thesupport.

'9. A grinding machine spindle structure including a housing or support,a first. spindle bearing mounted on the support for oscillation relativethereto, a second spindle bearing, means resiliently supporting thesecond spindlebearing on the support. a grinding wheel spindle journaledin said bearings, releasable clamp means for rigidly securing theresiliently mountedbearing in position on the support, a pusher member:carried by the housing in position toengage andveffeet aunidirecticnalurge against the resiliently supported bearing, means .foractuating the direction of the bearing, whereby on release of theclamping means said pushermember will" be efiective-Lfor determining theposition of the resiliently mounted bearing and the spindle supportedtherein, and means for varying the force exerted by the actuating meansagainst the pusher member.

10.'A grinding machine spindle structure including a housing or support,a first spindle bearing mounted on the support for oscillation rela--tive thereto, a second spindle bearing, means resiliently supporting thesecond spindle bearing on the support, a grinding wheel spindlejournaled in said bearings, releasable clamp means for rigidly securingthe resiliently mounted bearing in position on the support, a pushermember carried by the housing in position to engage and effect aunidirectional urge against the resiliently supported bearing, means foractuating the pusher member in the direction of the bearing, whereby onrelease of the clamping means said pusher member will be effective fordetermining the position of the resiliently mounted bearing and thespindle supported therein, and means for establishing a substantiallyconstant force reaction of the pusher member against the resilientlymounted bearing.

11. A grinding machine spindle structure including a housing or support,a first spindle bearing mounted on the support for oscillation relativethereto, a second spindle bearing, means resiliently supportin thesecond spindle bearing on the support, a grinding wheel spindlejournaled in said bearings, releasable clamp means for rigidly securingthe resiliently mounted bearing in position on the support, a pushermember carried by the housing in position to engage and effect aunidirectional urge against the resiliently supported bearing, means foractuating the pusher member in the direction of the bearing, whereby onrelease of the clamping means said pusher member will be efiective fordetermining the position of the resiliently mounted bearing and thespindle supported therein, and means for establishing a substantiallyconstant force reaction of the pusher member against the resilientlymounted bearing, said means including a hydraulically actuable pistonelement, a source of actuating medium reactable on the piston for urgingthe same in the direction of the pusher member, means for controllingthe coupling of the source with said piston element, and means forvarying the pressure exerted by the hydraulic medium against the piston.

12. A grinding machine spindle structure including a housing or support,a first spindle bearing mounted on the support for oscillation relativethereto, a second spindle bearing, means resiliently supporting thesecond spindle bearing on the support, a grinding wheel spindlejournaled in said bearings, releasable clamp means for rigidly securingthe resiliently mounted bearing in position on the support, a pushermember carried by the housing in position to engage and effeet aunidirectional urge against the resiliently supported bearing, means foractuating the pusher member in the direction of the bearing, whereby onrelease of the clamping means said pusher member will be effective fordetermining the position of the resiliently mounted bearing and thespindle supported therein, means for establishing a substantiallyconstant force reaction of the pusher member against the resilientlymounted bearing, said means including a hydraulically actuable pistonelement, a source of actuating medium reactable on the piston for urgingthe same in the direction of the pusher member, means for controllingthe coupling of the source with said piston element, means for varyingthe pressure exerted by the hydraulic medium against the piston, and acompression spring member intervening the pusher element and the pistonfor resiliently transmitting the forces exerted by the piston to thepusher member.

13. In a grinding machine, the combination with a housing, of a spindlemounted therein for movement relative thereto, and means for controllingthe movement of the spindle with respect to the housing including alocking member for said spindle, an abutment for cooperation with saidlocking member, a wedge block intervening the locking member and saidabutment, a hydraulically actuable piston for shifting said wedge blockas respects the abutment and locking memher to tighten or release theengagement of the locking member with respect to said spindle, a sourceof hydraulic actuating medium and a valve intervening said source andthe piston to determine the reaction of the pressure medium on thepiston, independent hydraulically actuable piston means to effect alimited releasing movement of the wedge block, a source of hydraulicactuating pressure for said piston and said piston means, and means fordetermining the reaction of the pressure medium as respects the pistonand the piston means, said means including a valve having a first seriesof portings to determine the coupling of the pressure medium to thepiston, and additional portings to determine the coupling of thepressure medium to said piston means.

14. In a grinding machine, the combination with a housing, of a spindlemounted therein for movement relative thereto, and means for controllingthe movement of the spindle with respect to the housing including alocking member for said spindle, an abutment for cooperation with saidlocking member, a Wedge block intervening the locking member and saidabutment, a hydraulically actuable piston for shifting said wedge blockas respects the abutment and looking member to tighten or release theengagement of the locking member with respect to said spindle, a sourceof hydraulic actuating medium and a valve intervening said source andthe piston to determine the reaction of the pressure medium on thepiston, independent hydraulically actuable piston means to effect alimited releasing movement of the wedge block, a source of hydraulicactuating pressure for said piston and said piston means, and means fordeterming the rection of the pressure medium as respects the piston andthe piston means, additional hydraulically actuable means to exert aradial urge against the spindle to resist work displacement thereof, anda control valve intervening the several hydraulically actuable means andthe source of hydraulic pressure, said valve having a first set ofportings for coupling the pressure medium to the wedge block piston anda second series of portings positionable simultaneously to couple theactuating pressure to the piston means and the hydraulically actuablemeans.

15. In a grinding machine having a work piece support and a resilientlysupported grinding wheel spindle, a yielding pressure member reacting onthe spindle to urge same in a direction to effect engagement of itssupported grinding wheel with a work piece held by the work piecesupport, and an opposed yielding resistor reacting on the spindle inopposition to said pressure member variably to resist movement of thespin-- dle toward the work piece support, a source of hydraulic pressureand conduit means coupling said source'with the pressure member and withthe resistor to determine their respective reactions on the spindle.

6. The combination with a precision grinding machine including a supportand a grinding wheel spindle mounted thereon for limited oscillatorymovement with respect to the support, of means reactable on the spindlefor controlling its oscillatory movement with respect to the support,said means including a first hydraulic cylinder, a piston movabletherein and hydraulical- 1y actuable in a direction toward the spindlefor effecting movement of the spindle in one direction, a secondhydraulic cylinder carried by the spindle support and of less diameterthan the first cylinder, said cylinder being disposed in opposedrelation to the first cylinder, a resistor piston carried by said secondcylinder having a less efiective area than the effective area of thefirst piston, a source of hydraulic pressure medium, means to connectsaid source to the first cylinder for actuation of the piston carriedthereby, conduit means interconnecting the cylinders, and a resistanceelement in said interconnecting conduit means for damping the reactioneffects of the pressure conditions in the respective coupled cylinders.

17. A grinder structure of the character described including anoscillatable grinding wheel spindle, a first yielding means forsupporting the spindle in a centralized position, a pressure actuablemember for efiecting an oscillation of the spindle in one direction, aresistor reacting on the spindle in opposition to said pressure member,means providing a hydraulic circuit for supplying actuating pressure tosaid member and to said resistor, and means for proportionately varyingthe pressure reactions on the pressure member and the resistor.

ALBERT H. DALL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,897,049 Hawes Feb. 14, 19331,967,163 Thearle July 17, 1934 2,142,021 Ernst et al. Dec. 2'7, 19382,308,843 Wilson Jan. 19, 1943 2,336,202 Walker Dec. 7, 1943

